Thrust deflector



June 28, 1966 M. R. SIMONSON 3,258,206

THRUST DEFLECTOR Filed Jan. 9, 1964 2 Sheets-Sheet 1 irraeey- June 28, 1966 M. R. slMoNsoN THRUST DEFLECTOR 2 Sheets-Sheet 2 Filed Jan. 9, 1964 /oR/OR ART 3,258,206 THRUST DEFLECTOR Marvin R. Simonson, Fairfield, Ohio, assignor to General Electric Company, a corporation of New York Filed Jan. 9, 1964, Ser. No. 336,823 6 Claims. (Cl. Z39-265.27)

This invention relates to a thrust control device for use in a vertical take-off and landing (VTOL) aircraft, and, more particularly, to fluid deflection means positioned in the exhaust outlet of a fluid propulsion engine.

A VTOL aircraft generally includes a fluid propulsion engine whose direction of thrust may be oriented to establish vertical thrust during ascent, descent, or hovering. Thrust orienting means which are suggested in the prior art include means for pivoting the entire engine about a horizontal Iaxis so as to direct the thrust downwardly.

' Fans have also been used in a similar, pivoting fashion, or

have been immovably mounted in the wing surfaces and powered by trip turbines or similar means. However, in aircraft designed for high speed flight, the Iattendant increase in weight incurred by the added pivoting means, the additional fan means, or the ofttimes cumbersome design of tiltable engines has tended to reduce the elllciency of operation and the limit of attainable speed.

In order to overcome the above-mentioned difllculties, thrust deflecting means are provided within the exhaust outlet of a ixedly mounted fluid propulsion motor. The deflecting means, when disposed parallel to the fluid flow path or streamline, should allow for normal engine operation in high speed, horizontal flight, When inthe deecting position, the dellecting means should provide a smooth flow of fluid downwardly and in some instances forwardly to .a limited degree for reverse thrust. The prior art deflecting means consist of a plurality of pivotable vanes whose pivot axes are horizontally disposed and positioned along a straight line in a forwardly and downwardly slanting plane inthe fluid motor exhaust oulet. straight line or planar positioning of the vane pivot axes which include the inability to maintain a smooth flow over the vanes during all angles of deflection. Inherently, in one of the blade positions, a high angle of attack is necessitated between the vanes and the fluid streamlines with the result that separation occurs between the fluid streamlines and the vane surfaces. More particularly, when the vane pivot axes are arranged in a straight line, a high angle of attack is caused by the inabality of two or more of the vanes to provide a smooth curved surface over which the fluid may be smoothly dellected and directed toward the remaining vanes at a low angle of attack.

When the vane pivot axes are arranged along a straight line, the high angle of attack problem cannot be remedied by cambering the vanes. A cambered Vane would allow smooth flow when in a dellecting position, but the cambered portion would then present a greater obstruction to fluid flow when oriented in a non-deflecting position. Conversely, a non-cambered vane is satisfactory when oriented in a non-dellecting position but there is greater fluid flow separation when it is positioned in a deflecting position if there is no provision for directing fluid toward the non-cambered vane at a low angle of attack.

The 4present invention overcomes these dilllculties of the prior art and achieves a greater degree of thrust efficiency by preserving laminar flow and eliminating separation between the fluid flow and deflecting vanes in all positions of the vanes.

It is therefore an object of this invention to provide an improved means for dellecting the motive fluid of a VTOL aircraft so that in all deflecting vane positions a United States Patent There are, however, attendant difficulties in a ICC low angle of attack is maintained between the vanes and the laminar fluid flow lines.

Another object of this invention is to provide an improved means for dellecting motive fluid of a VTOL aircraft so that separation does not occur between the fluid streamlines and the deflecting vanes while in any position.

An additional object is to provide a lightweight means for effectively deflecting exhaust fluid in a VTOL aircraft.

Further objects and advantages will become apparent as the following description proceds and the features of novelty are pointed out in the claims annexed to and forming part of this specification.

In carrying out the invention in one form Ithereof, thrust deflection means are disposed within the end of a fluid motor exhaust loutlet and within the confines of the fuselage or cowling in such a manner that the deflecting vanes preferably are pivotable about horizontally disposed parallel axes near the leading edge of the respective vanes. c

More particularly, the vane pivot axes are arranged perpendicular to a curved line. To illustrate, the mutually parallel axes may be considered as disposed within a curved plane which curves from the contour of the ontlet top wall to the contour of the outlet bottom wall, that is, it forms a generally smooth extension of the contour of both these walls. The smooth curvature along which the vane pivot axes .are disposed allows for the formation of a smooth extension when two -or more of the vanes are pivoted so that the trailing edge of one vane abuts the leading edge of an adjacent vane. The smooth extension .enables the fluid flow to remainlaminar while being directed at a low Aangle of attack -to the remaining deflecting vanes.

For a better understanding of the invention, reference is made to the accompanying drawings in which:

FIG. l indicates an aircraft incorporating one embodiment of -a fluid-deflecting device in accordance with `this invention;

FIG. 2 is a perspective view of the fluid-deflecting device of FIG. 1 illustrating the dellecting vanes positioned in a semi-dellecting position;

FIG. 3 is a sectional view in which the deflecting vanes are disposed in a non-deflecting position;

PIG. 4 is a sect-ional view similar to FIG. 3 except that the vanes are disposed in a deflecting position.

FIG. 5 illustrates the prior art positioning of the vane pivot axes along a straight line.

Referring to FIG. 1, an aircraft 1 is indicated having a fluid propulsion motor 2 mounted within the Iaircraft fuselage or engine cowling 3. The fluid propulsion motor 2 includes an exhaust conduit 4 having an exhaust outlet 5. The exhaust outlet 5 has a longitudinal -axis 6 which is essentially parallel `to the fuselage axis 7. At the exhaust outlet 5 is .a cutaway portion 8 in the bottom side and which extends downwardlythrough the exhaust conduit 4 and the fuselage 3. The cuatway portion allows for the downward deflection of exhaust fluid which normally passes rearwardly through the exhaust conduit 4. A plurality of dellecting vanes are arranged within the exhaust outlet 5 and can be pivoted so as to deflect the exhaust fluid downwardly through the cut-away portion 8.

The overall position of the deflecting vanes relative to the fuselage 3 and the exhaust outlet S may be appreciated by reference to FIG. 2. The dellecting vanes 9a, 9b, 9c, 9d and 9e are horizontally disposed in spaced relationship -across the exhaust outlet 5. In addition, the vanes are essentially confined within the sidewalls 18 of the fuselage or engine cowling 3 during all pivotal posi- Patented June 28, 1966- tions. Conventional deecting vane pivoting means are employed to pivot the deecting vanes 9a-e about their pivot axes 10.

The specific positioning of the vanes 9a-e and vane pivot axes 10 can be better appreciated by reference to FIGS. 3 and 4. The deflecting vanes 9a-e are pivotably mounted on deflecting vane pivot axes 10 which are disposed longitudinally of the deecting vanes adjacent the vane leading edges 13. The pivot axes 10 are mutually parallel and are disposed rst in spaced relationship along a curved line 11 between a top wall 15 and a second bottom wall 16 diametrically opposite of the exhaust outlet 5, the curved line 11 being a smooth extension of the contour of the top wall and the bottom Wall 16. The pivot axes 10 of the detlecting vanes 9rz-e are spaced along the curved line 11 with the distance between adjacent pivot axes being approximately equal to the chord of the adjacent vanes. When two or more of the vanes are pivoted so that their respective trailing edges abut the leading edges 13 of adjacent vanes, a smooth surface or curved extension of the contour of the top wall 15 or bottom wall 16 is formed. This ability to provide a smooth extension of the contour of either the top wall 15 or the bottom wall 16 when the pivot axes are arranged along a curved line which is a smooth extension of the contour of the top wall 15 and the bottom wall 16 enables the uid flow streamlines 12 to be more smoothly deflected at a low angle of attack to the vanes.

FIG. 3 illustrates the vane positions during normal, horizontal flight. The vane 9e is pivoted so that its trailing edge 14e abuts the vane leading edge 13 of the deecting vane 9d. Likewise, the trailing edge 14d of the deilecting vane 9d abuts the leading edge 13 of the deecting vane 9c. Hence, the surface whichis formed by the deecting vanes 9c-e is a smooth extension of the contour of the bottom wall 16 and permits smooth lami- .nar flow outwardly through the exhaust outlet 5 and parallel to the longitudinal exhaust outlet axis 6 while maintaining a low angle of attack relative to the defleeting vanes 9a-c.

When the blades are oriented in the deflecting position as illustrated in FIG. 4, the detlecting vane 9a is pivoted so that its trailing edge 14a abuts the leading edge 13 of the vane 9b. The vane 9b is pivoted downwardly and cooperates with the vane 9a to form a smooth surface which is an extension of the contour of the top wall 15. The smooth surface formed thereby gradually directs the uid low streamlines 12 downwardly through the exhaust outlet 5 and at a low angle of attack to the remaining deecting vanes 9c-e. The remaining deflecting vanes 9c-e may be pivoted downwardly and forwardly so as to establish a downwardly and forwardly directed thrust axis for both lift and reverse thrust.

It can be appreciated by reference to FIGS.v 3 and 4 that, by virtue of the curved line positioning of the vane pivot axes 10, the deecting vanes 9a-e may be oriented to provide a smooth extension of the contour of either the top wall 15 or the bottom wall 16 of the exhaust outlet and, thereby, preserve laminar flow by gradually changing the flow direction. Also, by changing the flow direction toward the other detlecting vanes, a low angle of attack is also preserved and the consequent loss of efciency through fluid flow separation and turbulence is avoided. The improved result of the curved line positioning of the deflecting vanes can be better appreciated by referring to FIG. 5 which illustrates the conventional, straight line 17 vane positioning. It may be noted from FIG. 5 that the straight line arrangement of vane pivot axes cannot provide smooth surfaces needed for directing laminar ow at a low angle of attack to the deflecting vanes during all positions of deection.

Although the present invention has been described as applied to uid propulsion moto'rs mounted within the aircraft fuselage for dellecting uid downwardly as disclosed in the preferred embodiment, the invention is also clearly applicable to wing-mounted motors, to outboardmounted motors at the rear portion of the fuselage, and to other aircraft powerplant arrangements. In addition, it is also not intended that the deflecting means be exclusively employed for downwardly directed thrust, but that the deflecting means may be employed for horizontal deection for turning the aircraft about a vertical axis while hovering.

It is intended, therefore, that while a specic embodiment of this invention has been shown and described, it is not desired that the invention be limited to the particular construction shown and described and it is intended by the appended claims to cover all modifications within the spirit and scope of this invention.

I claim:

1. A device for controlling the thrust direction in a VTOL aircraft which comprises,

`a fluid propulsion motor for mounting on an aircraft,

an exhaust outlet for said uid propulsion motor,

the normal fluid ilow through said exhaust outlet being generally parallel to the longitudinal axis of said exhaust outlet,

said exhaust outlet having a cutaway portion in the bottom side through which said iluid flow can be deflected downwardly from said outlet axis,

a plurality of delecting vanes pivotally mounted in said exhaust outlet at said cutaway portion for pivotal movement,

said vanes being pivotally mounted on xed axes disposed longitudinally of said vanes for pivoting about -said axes between deilecting and non-deflecting posiv tions,

said pivot axes being mutually parallel and spaced across said exhaust outlet along a curved line between the top and bottom walls of said outlet,

said curved line being a smooth extension of the contour of said top and bottom walls of said outlet.

2. A device for controlling the thrust direction in a VTOL aircraft which comprises,

a fluid propulsion motorfor mounting on an aircraft,

an exhaust outlet for said fluid propulsion motor,

the normal uid ow through said exhaust Outlet being generally parallel to the longitudinal axis of said exhaust outlet,

said exhaust outlet having a cutaway portion in the bottom side through which said fluid tlow can be deected downwardly from said outlet axis,

a plurality of deecting vanes pivotally mounted in said exhaust outlet at said cutaway portion for pivotal movement,

said vanes being pivotally mounted on fixed axes disposed longitudinally of said vanes and adjacent the leading edge of said vanes for pivoting about said axes between deflecting and non-deecting positions,

said pivot axes being mutually parallel and spaced across said exhaust outlet along a curved line between the top and bottom walls of said outlet,

said curved line being a smooth extension of the contour of said top and bottom walls of said outlet,

at least two of said vanes adjacent said top wall being arranged for engagement when said vanes are in a deflecting position to provide a smooth curved extension of said top wall contour over which said fluid flow is dellected downwardly at a low angle of attack to the remaining vanes.

3. A device for controlling the thrust VTOL aircraft which comprises,

a fluid propulsion motor for mounting on an aircraft,

an exhaust outlet for said fluid propulsion motor,

the normal fluid flow through said exhaust outlet being generally parallel to the longitudinal axis of said exhaust outlet,

said exhaust outlet having a cutaway portion in the bottom side through which said lluid flow c an be deflected downwardly from said outlet axis,

direction in a a plurality of deecting vanes pivotally mounted in said exhaust outlet at said cutaway portion for pivotal movement,

said vanes being pivotally mounted on fixed axes disposed longitudinally of said vanes and adjacent the leading edge of said vanes for pivoting about said axes between deecting and non-deilecting positions,

said pivot axes being mutually parallel and spaced across said exhaust outlet along a curved line between the top and bottom walls of said outlet,

said curved line being a smooth extension of the contour of said top and bottom walls of said outlet,

at least two of said vanes adjacent said top wall being arranged for engagement when said vanes are in a deecting position to provide a smooth curved extension of said top wall contour over which said uid flow is deflected downwardly at a low angle of attack to the remaining vanes,

and at least two of said vanes adjacent said bottom wall being arranged for engagement when said vanes are in a non-deecting position to provide a smooth curved extension of said bottom wall adjacent said cutaway portion over which said uid flow may be directed parallel to said outlet axis.

4. A device for controlling the thrust direction in a VTOL aircraft as set forth in claim 2 in which said vanes, when in the deflecting position, deect said iluid ow downwardly and forwardly for both vertical lift and reverse thrust.

5. A device for controlling the thrust direction in a VTOL aircraft which comprises,

a uid propulsion motor for mounting on an aircraft,

an exhaust outlet for said fluid propulsion motor,

the normal fluid ow through said exhaust outlet being generally parallel to the longitudinal axis of said exhaust outlet,

said exhaust outlet including a rst wall and a diametrically opposite second wall and having a cutaway portion in said second wall through which said uidv ilow can be deflected outwardly from said outlet axis,

a plurality of deflecting vanes pivotally mounted in said exhaust outlet at said cutaway portion for pivotal movement,

said vanes being pivotally mounted on xed axes disposed longitudinally of said vanes for pivoting about said axes between deecting and non-deiiecting positions,

said pivot axes of said vanes being mutually parallel and spaced across said exhaust outlet along a curved line between said rst wall and said second wall,

said curved line being a smooth extension of the contour of said first and second walls of said outlet,

at least two of said vanes positioned along said curved line adjacent said first wall being arranged for engagement when said vanes are in a deflecting position to provide a smooth curved extension of the contour of said rst wall over which said fluid flow is deflected outwardly from said outlet axis and at a low angle of attack to the remaining vanes,

and at least two of said vanes adjacent said second wall being arranged for pivotal engagement when said vanes are in a non-deflecting position to provide a smooth curved extension of the contour of said second wall over which said uid iiow may be directed parallel to said outlet axis. 6. A device for controlling the thrust direction of a VTOL aircraft which comprises,

a fluid propulsion motor for mounting on an aircraft,

an exhaust outlet for said uid propulsion motor,

said outlet having a top wall, a bottom wall, and side `walls,

the normal iluid flow through said exhaust outlet being generally parallel to the longitudinal -axis of said exhaust outlet,

said exhaust outlet having a cutaway portion in the bottom wall through which said fluid ow can be deliected downwardly and forwardly from said outlet axis,

a plurality of deecting vanes pivotally mounted in said exhaust outlet at said cutaway portion for pivotal movement,

said deiiecting vanes and said exhaust outlet being disposed substantially within the confines of said side walls,

said vanes being pivotally mounted on xed pivot axes disposed longitudinally of said vanes and adjacent the leading edge of said vanes for pivoting about said axes between deflecting and non-detiecting positions,

said pivot axes being mutually parallel and spaced across said exhaust outlet along a curved line between said top and bottom walls of said outlet,

said curved line being a smooth extension of the contour of said top and bottom walls of said outlet,

at least two of said vanes adjacent said top wall being arranged for engagement when said vanes are in a deflecting position to provide a smooth curved extension of said top wall contour over which said fluid ilow is deilected downwardly at a low angle of attack to the remaining vanes,

and at least two of said vanes adjacent said bottom wall being arranged for engagement when said vanes are in a non-deiecting position to provide a smooth 4curved extension of said bottom wall adjacent said cutaway portion over which said fluid flow may be directed parallel to said outlet axis and at a low angle of attack to the remaining vanes.

References Cited by the Examiner UNITED STATES PATENTS 2,802,333 8/1957 Price et al. 60-3554 2,879,014 3/ 1959 Smith et al. 244-12 3,016,700 1/ 1962 Howald 60-35.54 3,081,597 3/1963 Kosin et al. 60-35.54 3,087,303 4/1963 Heinze et al. 60-35.55 3,100,377 8/ 1963 Kosin et al. 60-35.54 3,126,171 3/ 1964 Stepniewski 244-12 FOREIGN PATENTS 1,066,499 l/ 1954 France. 1,007,179 4/ 1957 Germany.

MARK NEWMAN, Primary Examiner.

A. L. SMITH, Assistant Examiner. 

1. A DEVICE FOR CONTROLLING THE THRUST DIRECTION IN A VTOL AIRCRAFT WHICH COMPRISES, A FLUID PROPULSION MOTOR FOR MOUNTING ON AN AIRCRAFT, AN EXHAUST OUTLET FOR SAID FLUID PROPULSION MOTOR, THE NORMAL FLUID FLOW THROUGH SAID EXHAUST OUTLET BEING GENERALLY PARALLEL TO THE LONGITUDINAL AXIS OF SAID EXHAUST OUTLET, SAID EXHAUST OUTLET HAVING A CUTAWAY PORTION IN THE BOTTOM SIDE THROUGH WHICH SAID FLUID FLOW CON BE DEFLECTED DOWNWARDLY FROM SAID OUTLET AXIS, A PLURALITY OF DEFLECTING VANES PIVOTALLY MOUNTED IN SAID EXHAUST OUTLET AT SAID CUTAWAY PORTION FOR PIVOTAL MOVEMENT, SAID VANES BEING PIVOTALLY MOUNTED ON FIXED AXES DISPOSED LONGITUDINALLY OF SAID VANES FOR PIVOTING ABOUT SAID AXES BETWEEN DEFLECTING AND NON-DEFLECTING POSITIONS, SAID PIVOT AXES BEING MUTUALLY PARALLEL AND SPACED ACROSS SAID EXHAUST OUTLET ALONG A CURVED LINE BETWEEN THE TOP AND BOTTOM WALLS OF SAID OUTLET, SAID CURVED LINE BEING A SMOOTH EXTENSION OF THE CONTOUR OF SAID TOP AND BOTTOM WALLS OF SAID OUTLET. 